“We have been talking to our engineers to see if we can pull forward the launch," said Normand, adding the ratio of petrol to diesel models in India has skewed in favour of the latter, from 45:55 earlier to 20:80.

Nissan will launch the diesel variant before the end of this fiscal year, he said.

Following the deregulation of petrol prices, oil marketing companies have been raising petrol prices in line with global crude prices.

Frequent revisions have widened the gap between the costs of petrol and diesel by as much as ₹ 26 a litre. On 15 September, state-owned retailers raised petrol prices by ₹ 3.14 to ₹ 66.84 a litre in the Capital.

The resulting shift in buying patterns has forced car makers to advance launches of diesel variants and price new petrol models more competitively.

Earlier this month, faced with sluggish demand for the petrol variants of the Etios sedan and the Liva hatchback, the local arm of Toyota Motor Corp. advanced the launches of the diesel variants of both the models. Honda Siel Cars India Ltd had to pare prices of its petrol models to make them viable enough over the diesel rivals.

Experts say the shift is not permanent and it is only a matter of time before the price distortions are removed.

Kumar Kandaswamy, senior director at Deloitte Touché Tohmatsu India Pvt. Ltd, however, said Japanese manufacturers such as Nissan usually do not invest in diesel technology. “They will delay investments," he said offering two reasons.

“This is not something they are fundamentally strong in," he said, adding subsidies on diesel prices are not sustainable.

Japanese car makers, however, may increasingly consider buying technology from European manufacturers, he added, citing the example of Suzuki Motor Corp., which is sourcing diesel engine technology from Fiat SpA.

Suzuki is the parent of India’s largest car maker by sales, Maruti Suzuki India Ltd.

Dinesh Jain, chief executive at Hover Automotive India Pvt. Ltd, Nissan’s sales and marketing arm in the country, said car firms typically give a gap of nine months to a year before introducing a variant of a new model. But “we are trying to bring the diesel variant as soon as possible", he said.